Matlab throws error by using Interface Excel. Can solve please someone my problem stated below?

I got a problem by deploying my matlab code into excel, but getting following error and the file is created but is not accessible. I am using Matlab 2017a and Excel (Office 365).

Error using Interface.Microsoft_Excel_16.0_Object_Library.Workbooks/Open Invoke Error, Dispatch Exception: Source: Microsoft Excel Description: Excel cannot open the file 'RESULTS.xlsm' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file. Help File: xlmain11.chm Help Context ID: 0

Error in CountryVsSectorindices_20170128_test (line 503) invoke(Excel.Workbooks,'Open',File);

Thanks in advance for your help!